The invention relates to an optical apparatus for insertion into the open end of a gun barrel to produce short pulses of infrared light realistically simulating the firing of the gun.
Dry firing of long and hand-guns, that is, operation of the gun without ammunition has long been an accepted technique for improving skills. The technique is advantageous in that no firing range is required, and no ammunition is expended. The difficulty is that the marksman has no way of judging the results of his practice and little interest is provided during practice.
In order to provide a more realistic and interesting practice session, various systems have been proposed to produce an optical or other signal when a weapon is operated. One device currently available uses a source of light which is inserted into a hand-gun in place of the cylinder. When the trigger is pulled, a beam of light is produced which can be seen on a target some distance away to produce an indication of whether the firearm was properly aimed.
The difficulty with this system is that the gun is operated under practice conditions which are quite different from the actual firing conditions. The feel and weight of the gun will be different when the real cylinder is replaced. Since the device replaces the cylinder, a separate model is required for each different size and model of gun. In addition, it is difficult for such devices to be fired quickly enough in succession to be suitable for training. Parital disassembly of the hand-gun is required in order for the device to be used.
Other devices for simulating fire of a hand-gun have been developed which are inserted into the gun barrel. Such devices produce an optical or other signal in response to closing of a switch. Positioning and accurate operation of the switch is, however, difficult. The patent to Sump, U.S. Pat. No. 3,526,672, shows one device of this type. The patent to Giannetti, U.S. Pat. No. 4,048,489, describes a similar system in which a light pulse generator is contained in a gun sight holder.
The present invention relates to a unique apparatus for insertion into a gun barrel to produce pulses of light. The device is completely self-contained, and no external trigger is required. Rather, the vibrations produced by the hammer impact upon pulling of the trigger are detected to produce an electrical pulse which operates a light source to produce a short burst of pulses of light. The light can be detected by any suitable photo-sensitive device at the target to indicate if the hand or other gun was properly sighted so that if live ammunition had been used a hit would have resulted.
Since the device is inserted into the weapon without any modification or change in the weapon, the simulated fire is exactly identical to firing with live ammunition. No disassembly of the hand-gun is required; the present invention is simply slipped into the barrel. Since the bore diameters for all guns of similar calibre are roughly the same, one model can serve for weapons of all calibres which are roughly the same. It is particularly contemplated that one size would be appropriate for 44 and 45 calibre hand-guns and another size for 38 special, 9 mm, 357 magnum, and similar calibre hand-guns.
Another advantage of the present invention is its simplicity and reliability. Only a few components are required, and they can be made and assembled inexpensively and without difficulty.
In the specific embodiment of the invention described below, a piezoelectric sensor is used to detect the vibrations and produce an output signal which triggers an oscillator to apply a sequence of electrical pulses to a photo-diode, for example, an infrared emitting diode. The output of the photo-diode is gathered by a lens at the end of the barrel and directed to the target. A lens at the target preferably gathers the incident light onto a photodetector to produce a signal which can be used to provide any suitable indication of a hit. For example, a light could be illuminated, a sound could be given, etc. The unit is preferably powered by a plurality of batteries mounted in the unit and suitably connected to the circuit.
The output signal from the crystal is applied to the reset input of a counter via a logic gate which then prevents further resetting. The counter is connected to the oscillator and disables a gate between the oscillator and light source upon a first count. Upon a second count, the logic gate is again enabled to permit the counter to be again reset.
Any suitable case for the device can be utilized, for example, the case can be formed in a shell casing which can be separated to readily replace the batteries. By using short pulses of light, rather than a continuous beam of visible light, the most realistic simulation of actual fire is provided since any movement of the hand-gun after the burst has ceased will not produce an indication of a hit. Further, by producing only a short pulse of light, the lifetime of the batteries is maximized. A range of thirty to fifty feet is possible with hearing aid cells lasting for over one thousand shots.